Journal of the American Chemical Society最新文献

Perovskite tandem solar cells show promising performance, but non-radiative recombination and its progressive worsening with time, especially in the mixed Sn–Pb low-bandgap layer, limit performance and stability. Here we find that mixed Sn–Pb perovskite thin films exhibit a compositional gradient, with an excess of Sn on the surface—and we show this gradient exacerbates oxidation and increases the recombination rate. We find that diamines preferentially chelate Sn atoms, removing them from the film surface and achieving a more balanced Sn:Pb stoichiometry, making the surface of the film resistive to the oxidation of Sn. The process forms an electrically resistive low-dimensional barrier layer, passivating defects and reducing interface recombination. Further improving the homogeneity of the barrier layer using 1,2-diaminopropane results in more uniform distribution and passivation. Tandems achieve a power conversion efficiency of 28.8%. Encapsulated tandems retain 90% of initial efficiency following 1,000 h of operating at the maximum power point under simulated one-sun illumination in air without cooling.

Quantum dot (QD) provides a versatile platform for high-throughput processing of semiconductors for large-area optoelectronic applications. Unfortunately, the QD solar cell is hampered by the time-consuming layer-by-layer process, a major challenge in manufacturing printable devices. Here we demonstrate a sequential acylation-coordination protocol including amine-assisted ligand removal and Lewis base-coordinated surface restoration to synthesize conductive APbI₃ (A = formamidinium (FA), Cs or methylammonium) colloidal perovskite QD (PeQD) inks that enable one-step PeQD film deposition without additional solid-state ligand exchange. The resultant PeQD film displays uniform morphology with elevated electronic coupling, more ordered structure and homogeneous energy landscape. Narrow-bandgap FAPbI₃ PeQD-based solar cells achieve a champion efficiency of 16.61% (certified 16.20%), exceeding the values obtained with other QD inks and layer-by-layer processes. The conductive PeQD inks are compatible with large-area device (9 × 9 cm²) fabrication using the blade-coating technique with a speed up to 50 mm s⁻¹.

The electrification of trucks is a major challenge in achieving zero-emission transportation. Here we gathered year-long records from 61,598 electric trucks in China. Current electric trucks were found to be significantly underutilized compared with their diesel counterparts. Twenty-three per cent of electric delivery trucks and 30% of semi-trailers could achieve one-on-one replacement with diesel counterparts, while on average 3.8 electric delivery trucks and 3.6 electric semi-trailers are required to match the transportation demand that is served by one diesel truck separately. For diesel trucks that are capable of one-on-one replacement, electric trucks have 15–54% and 1–49% reductions in cost and life-cycle CO₂ emissions, respectively. Enhancements in usage patterns, vehicle technologies and charging infrastructure can improve electrification feasibility, yielding cost and decarbonization benefits. Increased battery energy densities with optimized usage can make one-on-one electrification feasible for more than 85% of diesel semi-trailers. In addition, with cleaner electricity, most Chinese electric trucks in 2030 will have lower expected life-cycle CO₂ emissions than diesel trucks.